20605823 has 12 divisors (see below), whose sum is σ = 25232760. Its totient is φ = 16731792.

The previous prime is 20605813. The next prime is 20605841. The reversal of 20605823 is 32850602.

It is not a de Polignac number, because 20605823 - 2²⁰ = 19557247 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20605792 and 20605801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20605813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10136 + ... + 11997.

It is an arithmetic number, because the mean of its divisors is an integer number (2102730).

Almost surely, 2^20605823 is an apocalyptic number.

20605823 is a deficient number, since it is larger than the sum of its proper divisors (4626937).

20605823 is a wasteful number, since it uses less digits than its factorization.

20605823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22166 (or 22159 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 20605823 is about 4539.3637219328. The cubic root of 20605823 is about 274.1553056003.

The spelling of 20605823 in words is "twenty million, six hundred five thousand, eight hundred twenty-three".